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Journal ArticleDOI

Anatomy of the Dicotyledons.

About: This article is published in American Midland Naturalist.The article was published on 1950-11-01. It has received 2511 citations till now.
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Journal ArticleDOI
TL;DR: Information from the Inside Wood database when combined with detailed information on ecological and geographical distributions of species, and subjected to more robust statistical analyses can be used to address a variety of questions on the evolution of wood structure and the ecological and phylogenetic significance of suites of features.
Abstract: Information from the Inside Wood database (5,663 descriptions) was used to determine the relative abundance of selected IAWA Hardwood List Features, for the whole world and for the broad geographic regions used in the IAWA List. Features that occur in more than 75 % of the records are: growth ring boundaries indistinct or absent, diffuse porosity, exclusively simple perforation plates, alternate intervessel pitting, and non-septate fibers. The geographic distribution of vessel element features found in this study is consistent with previous studies: ring porosity is a Northern Hemisphere adaptation; numerous, narrow, short vessel elements are more common in temperate regions than in tropical regions. Element size is related to habit, with few wide vessels being a syndrome that is virtually absent from shrubs and small trees. The co-occurrence of selected features, ones that earlier have been suggested to be correlated, was examined; e.g., tangential vessel arrangement and ring porosity, rare axial parenchyma and septate fibers, tracheids and exclusively solitary vessels that are of medium to wide diameter. Axial parenchyma features show geographic variation, with aliform to confluent parenchyma and bands more than 3 cells wide being primarily tropical in occurrence. Storied rays, crystals, and silica bodies are more common in the tropics than in the temperate Northern Hemisphere. For ray features, geographic patterns are less apparent. In Australia, incidences of some features (vestured pits, solitary vessels, radial/diagonal vessel arrangement) are influenced by the Myrtaceae being a major component of the flora. This paper is but a general overview. Information from the Inside Wood database when combined with detailed information on ecological and geographical distributions of species, and subjected to more robust statistical analyses can be used to address a variety of questions on the evolution of wood structure and the ecological and phylogenetic significance of suites of features.

182 citations

Journal ArticleDOI
TL;DR: It is concluded that expansigeny is the basic type of aerenchyma development in roots of flowering plants and that the presence of expansigenous honeycomb aerenchema in root cortices was fundamental to the success of the earliest flowering plants found in wetland environments.

180 citations

Book ChapterDOI
01 Jan 1995
TL;DR: In this paper, the authors focus on the ecological and physiological significance of stem water storage and the structural features that influence the same, including stomatal behavior, roofing patterns, and stem hydraulic conductivity.
Abstract: Publisher Summary This chapter focuses on the ecological and physiological significance of stem water storage The basic components necessary to examine the contribution of stem water storage are straightforward and include: determination of water uptake from the soil, water loss by the entire canopy, and changes in stem water content The water storage capacity of plant tissues is defined as the amount of water that can be withdrawn for a given change in driving force (water potential) and the structural features that influence the same is discussed Environments in which periods of high soil water availability are unpredictable, infrequent, and of short duration represent conditions well suited to within-plant water storage provided that net carbon gain can be sustained at very low total water loss rates In most plants, stem water storage appears to be most important in enabling them to survive periods of drought In addition, stem water storage may provide a strategic reserve during limited periods of adverse environmental conditions (eg, giant rosette plants, dry-season flowering in tropical trees) Understanding the temporal dynamics of stem water utilization requires that it be examined in the context of stomatal behavior, roofing patterns, and stem hydraulic conductivity Because of its close proximity to the transpiring surfaces, coordination between the hydraulics and patterns of water use are necessary to prevent the depletion of stem water stores prior to the onset of extreme conditions

176 citations

Journal ArticleDOI
TL;DR: Phylogenetic analyses strongly support the repeated gain and loss of EFNs across plant clades, especially in more derived dicot families, and suggest that EFNs are found in a minimum of 457 independent lineages.

173 citations


Cites background from "Anatomy of the Dicotyledons."

  • ...…(Bentley, 1977), Goodeniaceae (Bentley, 1977), Hydrangeaceae (Zimmermann, 1932), Icacinaceae (Koptur, 1992), Musaceae (Koptur, 1992), Olacaeae (Metcalf and Chalk, 1971) and Stryracaceae (Vesque, 1886); and (c) genera without any species identification, if they could not be confirmed by other…...

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  • ...We omitted (a) families with only a single, unpublished report of EFNs: Aristolochiaceae and Clusiaceae; (b) families with a single, published report of EFNs that could not be confirmed: Alismataceae (Schnell et al., 1963), Ancistrocladaceae (Metcalfe 1951 in Koptur, 1992), Annonaceae (Koptur, 1992), Bruneliliaceae (Watson and Dallwitz, 1992 onwards), Caryophyllaceae (Bentley, 1977), Goodeniaceae (Bentley, 1977), Hydrangeaceae (Zimmermann, 1932), Icacinaceae (Koptur, 1992), Musaceae (Koptur, 1992), Olacaeae (Metcalf and Chalk, 1971) and Stryracaceae (Vesque, 1886); and (c) genera without any species identification, if they could not be confirmed by other means (26 genera)....

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Journal ArticleDOI
TL;DR: The molecular analysis of stomatal development promises advances in understanding intercellular signaling, the control of the plane and polarity of asymmetric division, the specification of cell fate, and the regulation of cell differentiation and shape.
Abstract: Stomata consist of two guard cells around a pore and act as turgor-operated valves for gas exchange. Arabidopsis stomata develop from one or more asymmetric divisions followed by the symmetric division of the guard mother cell. Stomatal number is partly a function of the availability of smaller epidermal cells that are competent to divide asymmetrically. Stomata are spaced apart from each other by at least one neighbor cell. Pattern generation may involve cell-cell signaling that transmits spatial cues used to orient specific classes of asymmetric divisions. TOO MANY MOUTHS may function in receiving or transducing these cues to orient asymmetric divisions. TMM also is a negative or positive regulator of entry into the stomatal pathway, with the direction of the response dependent on organ and location. STOMATAL DENSITY AND DISTRIBUTION1 is a negative regulator of stomatal formation throughout the shoot and encodes a processing protease that may function in intercellular communication. FOUR LIPS apparently controls the number symmetric divisions at the guard mother cell stage. In some organs, such as the hypocotyl, the placement of stomata may be coordinated with internal features and involves genes that also regulate root hair and trichome formation. Other mutations affect guard cell morphogenesis, cytokinesis, and stomatal number in response to carbon dioxide concentration. The molecular analysis of stomatal development promises advances in understanding intercellular signaling, the control of the plane and polarity of asymmetric division, the specification of cell fate, and the regulation of cell differentiation and shape.

172 citations


Cites background from "Anatomy of the Dicotyledons."

  • ...Arabidopsis and other members of the Brassicaceae exhibit anisocytic complexes where the stoma is surrounded by three cells, one of which is smaller (Figures 5 and 9B; Metcalfe and Chalk, 1950; Pant and Kidwai, 1967)....

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